Shocking experience at practice last night....
1 power outlet, 2 power strips. One strip pumping my bass rig, PA, pedalboard, and vox processor, the other powering the guitar amp and pedalboard.
We hook everything up and I lean over to check the mic only to get arc-zapped in the lip. F*ck that stings. Touch the mic again with my hand, sure enough its buzzin.
We'd just finished a tree sesh, so in our great wisdom I make guitarist grab the mic... no problem. Must have been a fluke... grab it again, shockshockshock. Take off my bass, touch the mic no problem. Put the bass on again, shockshockshock. Tell guitarist to grab it again (at this point he's rofl'ing at my pitiful troubleshooting)... he grabs the mic, I grab his arm and we both get zapped (take that f'cker!)
Guitarist notes that my bass and amp are 28+ years old and that may be part of the problem. At this point my heart is beating fairly hard and I'm a bit on edge (what a great day to forget to stop at the liquor store on the way to jam) so I'm leery to grab the mic again. The ONLY changed variable in the whole room was my guitarist's Laney is in the shop so he brought his Peavey combo back out. That combo is running from the same outlet, so I'm thinking maybe that had something to do with it....
Finally, I notice the little extra switch on my Acoustic amp that I never knew its purpose. GND / REV. A quick Google search concludes this reverses the ground... and in its shockingly electric state, happens to be in REV. I switched it back to GND, hesitantly grabbed the mic.... no shock! Proceeded to play and sing the rest of the night with no issues.
SOOOO why did I just waste everyone's time here? I'm wondering if when the Laney comes back, I can expect a hearty zap from the mic. I dont know why I had it in REV ground anyway, I think I had some hum at a jam once, and never set it back to normal GND. Is it as simple as the switch solved my problem? Or do you think theres still a grounding issue, either in my amp or my guitarists? The power cable was recently replaced on mine (recently = last year) and Id never experienced problems before. Apparently my guitarist's amp has some ground switches in the back too, we didnt mess with those.
So I solved the initial problem, but I really really want to mitigate that risk in the future. The zaps weren't bad to a quick touch but the first one on the lip and 2nd one where I grabbed the whole mic sure did suck a big bag of d!cks. Any suggestions to preventing this in the future?
1986 passive Ric and 1974-ish solid-state Acoustic rig. I'm buying a cheap outlet tester to throw in the music bag but considering the amps were on the same outlet I dont think that would have been the problem, no?